Low-watek-alarm apparatus for steam-boilers



N. PETERS, PNGTO-UTHOGRAPHER, WASHINGTON. D. c.

UNITED sTATEs PATENT oEEroE CHARLES H. BROWN, OF FITCHBURG,MASSACHUSETTS.

LOW-WATER-ALARIVI APPARATUS FOR STEAM-BOILERS.

Specification forming part of Letters Patent No. 29,455, dated August 7,1860; Reissued May 19,

Y 1863, No. 1,473.

To all whom 'it may concern:

Be it known that I, CHARLES H. BRowN, of Fitchburg, in the county oflVorcester and State of Massachusetts, have invented a new and ImprovedLow-Vater-Alarm Apparatus for Steam-Boilers; and I do hereby declarethat the following is a full, clear, and exact description of the same,reference being had to the accompanying drawing, forming part of thisspecification, said drawing representing a central vertical section ofthe apparatus.

My invention consists in a novel system or arrangement of pipes and arod for attaching to a steam boiler a steam whistle or its equivalentand a lever for operating the valve of the said whistle or equivalentwhereby when the water in the boiler falls below a certain level, theexpansion of the said pipes by the admission of steam thereinto iscaused not only to move the valve from its seat but at the same time tomove the seat away from the valve, thereby as it were producing a doubleaction of the whistle valve or its equivalent and insuring a prompt andcertain opening` of the valve to sound the alarm.

To enable those skilled in the art to make and use my invention I willproceed to describe its construction and operation- A, and B, are twoupright pipes, of brass or other metal having a suitable capability ofexpansion by heat connected together at their lower ends by a bend C,like an inverted siphon. The said band which is intended to stand somedistance above or away from the boiler has attached to it a single pipeD, which serves to connect it with the boiler, the said pipe being soarranged that its mouth opens into the boiler at a level below which itis desired that the water in the boiler shall never fall. At the top ofthe pipe A, which is shorter than the pipe B, there is secured asteamwhistle IV, the seat a, of whose valve is rigidlyl secured to the saidpipe A. At the top of the pipe B, which extends some distance above A,there is an air chamber E.

Between the two pipes A, and B, there is arranged an upright iron rocLF,the lower part of which is secured to a fixed cross piece Gr, arrangedwithin the bend C, by means of two nuts b, and c, fitted to a screwthread cut on the rod, one of the said nuts being above and the otherbelow the said cross-piece and the rod passing through the said.cross-piece. The upper part of the said rod 1s slotted to receive ythelever H, which `operates the valve of the whistle, one end of' the saidlever being attached by a pin joint el, to the air chamber E, or to theupper part of the pipe 4B, and the other end extending across the heade, of the stem e, of the whistle valve This valve is of the puppet kindand. closes with an upward movement. It has a spiral spring g, appliedto its stem c, between the head c, thereof, and the top of the whistle,for' the purpose or' keeping it closed when'there is no pressure ofsteam in the boiler. Vhen the pressure in the boiler is slightly abovethat of the atmosphere it is sufficient to close the valve without thespring. The slot L, provided in the rod F, :tor the lever H, is deepenough to allow a slight amount of play upward and downward to the saidlever. Some distance below the said lever there is secured between thepipes A, B, a fixed guide I, to keep the rod F, upright.

The operation of the apparatus is as follows: So long as the level ofthe water in the boiler is above the mouth of the pipe D, and there isany considerable pressure of steam, the pipes A, and B, are kept filledwith water which being out of reach of the circulation of the waterwithin the boiler does not get heated nearly so hot as the steam in theboiler and while this is the case the pipes A, and B, do not expandsufficiently to open the valve but as soon as the water in the boilergets below the mouth of the pipe D, the water falls from within thepipes A, B, C, D, by gravitation and its pla-ce is supplied with steamwhich fills the said pipes and heats the pipes A, B, to such a degree asto produce almost instantaneously such an increase of length byexpansion that the valve f, is opened to permit the escape of steam t/othe whistle to give the alarm, by the upward movement of the valve seat,a away from the valve and the simultaneous downward movement of thevalve away from the seat, such movement of the seat being produceddirectly by the expansion lengthwise of the pipe A, and the movement ofthe valve by the expansion of the pipe B, which raises the end of thelever which is attached to it and causes the other end to be depressedupon the head of the valve stem, the rod F, which is never perceptiblyexpanded constituting the fulcrum of the lever. As soon as the Water hasrisen above the level of the mouth of the pipe D, it is forced up intothe pipes A, and B, again as fast as the steam can be condensed thereinand the pipes becoming cool and contracting the valve closes by thedownward movement of the seat due to the contraction of A, and upwardmovement of the valve under the influence of the steam pressure,permitted by the action of the lever produced by the contraction of B.

The air chamber E, is for the reception of the air, Which Will get intothe pipe B, and which Without the air vessel or a Very greatly extendedlength of pipe Would prevent the steam lling the Whole or as much of thesaid pipe as is desirable to produce the requisite degree of expansion.The outlet provided by the Whistle obviates the necessity of an airchamber on the pipe A, as the air can be let out by depressing andopening the valve. The play allowed to the lever H, in the slot h,permits the expansion which is due to the heat of the Water in the pipesto take place VWithout opening the valve. The nuts Z9, c, serve toadjust the rod so that the valve may open the instant a certain degreeof expansion of the pipes is arrived at.

What I claim as my invention and desire to secure by Letters Patent iS-The arrangement of the connected pipes A, and B, the slotted rod F, orother fixed fulcrum, the lever H, and the Whistle 7, or its Vequivalentwhereby the expansion of the pipes not only causes the operating valveof the Whistle or equivalent to move from its seat, but the seat to movesimultaneously from the valve substantially as and for the purposeherein specified.

CHARLES H. BROWN.

Witnesses:

W. J. MERRIAM, DANL. CRoss.

